The present invention relates to a polishing apparatus and a polishing method which is, in particular, suitable for polishing of a semiconductor wafer.
FIG. 16 shows a typical semiconductor wafer polishing apparatus for conducting a precise polishing process for a semiconductor wafer which process is referred to as "chemical-mechanical planarization" (CMP). The polishing apparatus includes a turntable 100 and two wafer carriers 101, 102 which are respectively rotated around their respective center axes in the directions designated by arrows A, B and C. The turntable is provided, on its top surface, with a polishing pad. Each of the wafer carriers 101, 102 holds a wafer on the bottom surface thereof. The wafer carriers are symmetrically positioned relative to the center axis of the turntable. The apparatus further includes a slurry supply nozzle 104. In operation, wafers carried by the carriers 101, 102 are engaged with the polishing pad on the turntable 100 while the turntable and the wafer carriers 101, 102 are rotated and the slurry supply nozzle 104 continuously supplies a slurry onto the polishing pad. The wafers are polished mechanically and chemically by means of the polishing pad and the slurry. The wafer carriers 101, 102 are swingable in the directions designated by arrows D and E, respectively, to enable the wafers to be mounted on and removed from the wafer carriers.
In such a polishing apparatus, it is desirable that consumption of slurry, which is expensive, be minimized, so far as a high polishing performance in term of polishing rate, evenness of a polished surface of a wafer and so on is maintained. Thus, there is a need to effectively transfer the slurry to the wafers after the slurry is applied to the polishing pad.